Light metal wheel

ABSTRACT

A wheel, particularly a light metal wheel, for motor vehicles, essentially consists of a spoke wheel center ( 20 ) and a rim ( 10 ). In order to reduce weight and increase the bending strength, which is of great significance in regard to contact with curbstones and potholes, profile segment ( 31 ) in the form of half-shell units, which forms a continuous hollow chamber ( 41 ) in the direction of the circumference, at least in sections, are provided in the area of an external base of the rim ( 14 ).

This is a Continuation, and claims the priority of the filing date, ofSer. No. 10/070,578, filed on Jul. 24, 2002 now U.S. Pat. No. 6,783,190B1.

The invention relates to a wheel, particularly a light metal wheel formotor vehicles, wherein each such wheel comprises a spoke wheel centerand a wheel rim, in which the wheel rim has an inner bead seat making atransition to an internal horn of the rim, and an outer bead seat makinga transition into an external horn of the rim.

BACKGROUND OF THE INVENTION

1. The Technical Field

Such types of wheels enjoy very great popularity, particularly in aconstruction as light metal wheels, since, in addition to an increasedoverall aesthetic appearance of the motor vehicle, additional technicaladvantages can be attained.

2. The Prior Art

In entirely general terms, the present trend is towards reducing theweight of the wheel as much as possible. This is an additional reasonfor the increasing spread of light metal wheels. The savings in weightrelative to conventional steel wheels that is achieved is frequently notvery high, however, since the light metal alloys that are used mostly donot have the strength of steel. Such wheels must therefore be designedwith greater wall thicknesses, as the result of which the weightadvantage is partially lost again.

The task which forms the basis for the present invention is thereforethat of further developing a wheel, particularly a light metal wheel formotor vehicles, in such a manner that it no longer has the disadvantagesstated. In particular, a wheel should be created which permits anadditional reduction of weight or an improvement of the mechanicalcharacteristics relative to conventional wheels.

SUMMARY OF THE INVENTION

This problem is solved by means of a wheel which is provided withprofile segments which continuously form at least one hollow chamber inthe direction of the circumference, which profile segments, at least insections, are provided in the area of the internal bead seat and theexternal bead seat.

Advantageous forms of implementation of the invention are stated herein.

The invention is based on the idea of forming hollow chambers in areasof the wheel that are subject to particularly heavy stresses, thus, inthe area of the internal horn of the rim and the external horn of therim.

These hollow chambers are comparable with closed hollow chamber profilesections, which are known entirely generally from the area of lightconstruction and which permit a considerable increase in the strength.In concrete terms, it is provided to apply profile segments, which eachform hollow chambers in the direction of circumference, in the area ofthe internal base of the rim and/or of the external base of the rim. Asa general rule, the hollow chamber is developed continuously in thedirection of circumference, so that an increase in rigidity, distributedoptimally uniformly over the circumference, is provided. In the area ofthe internal horn of the rim, the increase in the bending strength isused to improve the so-called impact behavior. In the area of theexternal horn of the rim, the aspect of the weight reduction is mostprominent.

One particularly weight-saving construction results if the hollowchamber assigned to the external base of the rim is combined with hollowchamber spokes. In this manner, a hollow chamber structure, which makespossible excellent rigidity values with simultaneously minimum weight,can be provided.

The construction of the hollow chambers is carried out by means ofprofile segments which are attached to the wheel rim in the area of theinternal base of the rim or of the external base of the rim and areconnected into a closed hollow profile.

One particularly simple construction results if the profile segments aredeveloped as shell units, particularly as half-shell units. These can bepre-manufactured in a simple way and manner and, as a rule, applied tothe external circumference of the wheel rim. The individual segments canbe connected with one another by means of connection techniques whichare known per se and have already proven their value, such as welding,adhesion, or flanging, for example. The connection is likewise carriedout towards the wheel rim, so that a closed hollow chamber profile canbe produced.

The geometrical configuration of the profile segments can be selected insuch a manner that optimal results can be achieved in relation to thebending strength that is being striven for. As a rule, however, at leastone section of the specific profile segments of the base of the rim—thatis to say, the internal base of the rim or the external base of therim—is configured so that the geometry is accordingly provided in thoseareas as a seat or supporting surface for the tires.

In accordance with one preferred variant, the profile segments aredeveloped in a congruent manner in the area of the internal base of therim and the profile segments in the area of the external base of therim. They can consequently be stored in inventory as so-called identicalparts, and permit optional application in the internal- or in theexternal area.

Finally, it is also possible to form the profile segments, by means of anon-cutting shaping process, from an annular bar integrally formed onthe wheel rim, particularly one cast integrally in a single piece.So-called ductile materials, which can be transformed under coldconditions, or cast alloys, which can be transformed under warmconditions, are suited for this.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1: Wheel in a half-section, first variant;

FIG. 2: Wheel in a half-section, second variant;

FIG. 3: Wheel in a half-section, third variant;

FIG. 4: Wheel in a half-section, fourth variant;

FIG. 5: Wheel in a half-section, fifth variant;

FIG. 6: Wheel in a half-section, sixth variant;

FIG. 7A is an illustration of the seventh variant in initial form, FIG.7B shows a transitional form, and FIG. 7C shows a final form;

FIG. 8: Wheel in a view from the front.

FIG. 9: A side elevation of a wheel according to preferred embodimentsof the invention, showing how two profile segment half shells may bejoined.

DETAILED DESCRIPTION OF THE INVENTION

The wheel rim (10) has an internal base of the rim or bead seat (16) andan external base of the rim or bead seat (14). These each make atransition axially outwardly into an internal horn or flange of the rim(18) and an external horn or flange of the rim (12). A tire, notdepicted here, which is seated on the internal base of the rim (16) andthe external base of the rim (14), and is laterally applied on theinternal horn of the rim (18) and the external horn of the rim (12), isheld between the internal horn of the rim (18) and the external horn ofthe rim (12).

The wheel rim (10) makes a transition into a spoke wheel center (20),which has a multiplicity of spokes (22). The spokes (22) are, forreasons of weight savings, constructed as hollow spokes and each have aspoke hollow cavity (24). All variants of construction are accordinglyin agreement.

The variants of construction depicted in FIG. 1 to FIG. 3 have profilesegments (31, 32, 33) which are attached in different configurations inthe area of the external base of the rim (14). They each have the shapeof half-shells, so that two profile segments (31, 32, 33) are eachapplied, from the outside, onto the wheel (1) in the area of theexternal base of the rim (14), and are connected solidly both with oneanother as well as well as with the wheel (1). In this way, a hollowcavity (41, 42, 43), which is configured continuously in the directionof circumference, is formed in the radial direction on the inside. Acommunicating connection with the spoke hollow cavities (24), throughwhich an extremely stable and, at the same time, a rigid hollow chamberconstruction, is brought about, is present in the area of the spokes(22). This guarantees an impact behavior which is considerably improvedin relation to the previously known contractions, which [impactbehavior] is particularly important in regard to unintended curbstonecontacts and driving over potholes. At the same time, this constructionis very light, as the result of which the total weight of the wheel (1)is reduced considerably.

In the variant in accordance with FIG. 1, the profile segment (31) isconfigured in an essentially “L”-shape and is axially supported, on oneend, on the external horn of the rim (12) and radially, on the otherend, in the area of the spokes (22) proceeding outwardly.

FIG. 9 is a side elevation of a wheel (1) showing how profile segmenthalf shells (31, 32, 33) may be joined at 100, by means of any knownmethod of joining, such as welding, adhesion or flanging.

In the variant of construction in accordance with FIG. 2, the profilesegment (32) is beveled along a larger cross-sectional section on theexternal horn of the rim (12), over its complete surface. In this way,an optimal supporting of that area of the profile segment (32) whichserves as tire seat is guaranteed.

The variant in accordance with FIG. 3 is primarily distinguished fromthat in accordance with FIG. 2 through the fact that the profile segment(33) is guided out beyond the middle axis of the wheel (1). In this way,a sharp increase in the bending strength is achieved.

The variants of design in accordance with FIGS. 4 to FIG. 6 have aprofile segment (31) which is in agreement with the variant of design inaccordance with FIG. 1. In addition, profile segments (34, 35, 36),which each form additional hollow chambers (44, 45, 46), are provided inthe area of the internal base of the rim (16). The profile segments (34,35, 36) are, in turn, designed as half-shell units, which are solidlyconnected both with one another as well as with the wheel (1). Theythereby increase the bending strength in the area of the internal hornof the rim (18), as the result of which the impact behavior is alsodecisively improved in this area. This is particularly important here inrelation to driving over potholes.

In the variant of design in accordance with FIG. 4, the profile segments(34) are applied to be positioned radially and externally on the wheel(1) and form, together with the internal horn of the rim (18), theinternal base of the rim (16). In the radial direction, the profilesegments (34) support the tires directly. (1) and form, together withthe internal horn of the rim (18), the internal base of the rim (16). Inthe radial direction, the profile segments (34) support the tiresdirectly.

In the variant of design in accordance with FIG. 5, the profile segment(35) is provided positioned radially internally, and thereby servesexclusively for increasing the rigidity. The tire seat is additionallyformed directly on the wheel rim (10).

FIG. 6 depicts a variant in which the profile segment (36) is designedto be congruent with the profile segment (31). This variant makespossible an identical design of the parts, since the profile segments(31, 36) can optionally be used in the area of the internal base of therim (16) or of the external base of the rim (14).

FIGS. 7A, 7B and 7C depict an additional variant, in which a profilesegment (34) in agreement with that of FIG. 4 is used in the area of theinternal base of the rim (16). The characteristic feature lies only inthe fact that, during the shaping of the wheel (1), a molded blank (50)(see FIGS. 7A, 7B) is used which has, in the in the area of the externalbase of the rim (14), an annular bar or radially extending flange (30)having a radially outwardly disposed free edge (51) which is, in a coldor hot transformation process, formed into a profile segment (37) and isbrought to application on the external horn of the rim (12). In thismanner, the profile segment (37) is formed in an integral manner withthe wheel (1) without requiring additional components for therealization of the invention. Although not depicted here, acorresponding procedure is also possible in the internal base of the rim(16). The embodiment of FIG. 7C also includes hollow chamber 47.

Although the concept in accordance with the invention is essentiallyalso suitable for wheels of steel, it preferably finds application inlight metal standard norm EN 573-3, namely EN AW-AIMg3 or ENAW-AISilMgMn, are suitable as materials for the profile segments. Bothof the last-named materials involve so-called ductile materials, whichcan be transformed under cold conditions. Furthermore, it is obviouslypossible to manufacture the wheel and the profile segments from the samematerial.

Listing of References:

-   1 Wheel.-   10 Wheel rim.-   12 External horn of the rim.-   14 External base of the rim.-   16 Internal base of the rim.-   18 Internal horn of the rim.-   20 Spoke wheel center.-   22 Spoke.-   24 Spoke hollow cavity.-   30 Annular bar or radially extending flange-   31 Profile segment.-   32 Profile segment.-   33 Profile segment.-   34 Profile segment.-   35 Profile segment.-   36 Profile segment.-   37 Profile segment.-   41 Hollow chamber.-   42 Hollow chamber.-   43 Hollow chamber.-   44 Hollow chamber.-   45 Hollow chamber.-   46 Hollow chamber.-   47 Hollow chamber.-   50 Molded blank.-   51 Radially outwardly disposed free edge.

1. A wheel, for motor vehicles, comprising: spoke wheel portion (20) anda wheel rim (10); wherein the wheel rim (10) further comprises aninternal bead seat (16) and an external bead seat (14) which makes atransition into an internal flange (18) and an external flange (12);wherein at least one profile segment (31, 32, 33, 34, 35, 36, 37) whichcontinuously forms at least one hollow chamber (41, 42, 43, 44, 45, 46,47) in the direction of the circumference, at least in sections, isprovided proximate the internal bead seat (16) and/or of the externalbead seat (14); and wherein the at least one profile segment (31, 32,33, 34, 35, 36, 37) is initially configured as a substantially radiallyextending flange (30) emanating from the wheel rim between the inner andouter flanges, and having a radially outwardly disposed free edge (51),which radially extending flange (30) is reformed to curve back upon thewheel rim with the free edge (51) rejoined to the wheel rim, to define ahollow space therebetween, and further wherein the substantiallyradially extending flange (30) emanating from the wheel rim between theinner and outer flanges is bent axially outwardly toward a face of thewheel in a single step to define a hollow chamber.
 2. A wheel, for motorvehicles, comprising: spoke wheel portion (20) and a wheel rim (10);wherein the wheel rim (10) further comprises an internal bead seat (16)and an external bead seat (14) which makes a transition into an internalflange (18) and an external flange (12); wherein at least one profilesegment (31, 32, 33, 34, 35, 36, 37) which continuously forms at leastone hollow chamber (41, 42, 43, 44, 45, 46, 47) in the direction of thecircumference, at least in sections, is provided proximate the internalbead seat (16) and/or of the external bead seat (14); and wherein the atleast one profile segment (31, 32, 33, 34, 35, 36, 37) is initiallyconfigured as a substantially radially extending flange (30) emanatingfrom the wheel rim between the inner and outer flanges, and having aradially outwardly disposed free edge (51), which radially extendingflange (30) is reformed to curve back upon the wheel rim with the freeedge (51) rejoined to the wheel rim, to define a hollow spacetherebetween, wherein the internal flange (18) and the external flange(12) each extend radially outwardly of the at least one hollow chamber.